What To Look For When Testing An Existing Home’s Well & Septic System

When buying an existing home that has a well and septic system, many Buyers wonder why they should test these systems if everything seems to work well inside the home.  It is advisable to have both well and septic inspections done by an experienced professionals in their respective fields and most Purchase and Sale agreements provide for Buyers to be able to do such inspections/tests.

I’ll add more details so that you understand what you should test for. Remember, the testing is an opportunity for you to confirm that both the well and septic system will provide you with years of trouble free service and also provide you with not only potable (drinkable) water, but with water quality that YOU want to live with.

On the well, you want to evaluate three issues. I’ll speak from the prospective of modern drilled wells as that’s what’s most common in my area and in the new construction that I deal with:

1. Yield: Should be tested to confirm what its yield (GPM – Gallons Per Minute) is and the records on file should give you an idea of the well depth and static level (natural level below surface of ground that water settles at). These two pieces of info give you an idea of how much water your well will deliver. The deeper the well, the more reserve water you might have available for use. In a well with 6″ casing, there is 1.5 gallons per foot of water column (drill depth – static level – pump distance off bottom of well = water column x 1.5 = total gallons in ground).

2. Pressure/Output Capacity: This is related to yield because a low yield would limit the best delivery system’s capacity to provide you with water on demand. The deeper the well, the larger the pump must be to push the water out of the well when you put stress on it during peak use and when the static level is drawn down. Larger pressure tanks inside the home are generally better in that they will put less cycles on the well pump. If you are planning to add an irrigation system, these two issues need to be evaluated by someone knowledgeable so that you can confirm that the existing well has the capacity to support the load that an irrigation will put on the well.

3. Water Quality: There is a difference between water that is potable (safe for human consumption) and water that is high quality. Learn more about any treatment system that is already installed. If there is an existing water treatment system, its backwash drain line should NOT be tied into the septic system drain. The current public health code prohibits this. Most well water tests are for all forms of contaminants including but not limited to bacteria, hardness, pesticides, nitrate, VOCs, radon and metals. After that, the biggest concern I have with water quality is that if the natural water is aggressive, meaning low in PH and other factors are present, that condition needs to be corrected via a treatment system in order to avoid the copper plumbing in the home from getting damaged and failing. If you see green residue in the toilet tank, that’s possibly a sign that the copper plumbing may be negatively affected by the water quality. I’ll add one test to Len’s list and that you might want to test for fluoride if you have young children knowing what the natural level of fluoride in the water is will allow you to set a proper supplemental level of fluoride to provide your children with should you want to do that (it helps with teeth development).

On the septic system, there are a number of things to look at and consider:

1.  You should obtain is the septic system as-built.  It will provide you with information on where the septic tank is located along with the primary and reserve leaching areas are located.  This is important if you are considering putting on an addition to the home or installing a pool since there are separating distances that must be adhered to and if the back yard is used up by the septic system, you may be prohibited from installing an addition or pool.  You should also look at the Permit To Discharge to see what limitations were set by the sanitarian when the system was installed.  If the system is designed for a 3 Bedroom home and you see the listing for the home saying 5 bedrooms, there may be improvements to the home that were done without permits or at a minimum, you may want to confirm that the septic system was expanded and improved to accommodate the current homes use and sanitary output.

2.  Modern septic systems have two-compartment septic tanks and then primary and secondary leaching areas.  The tank typically will get pumped when inspected and the pumping costs are normally paid for by the Seller.  Newer systems also have effluent filters that prevent solids from leaving the tank and then ruining the leaching area.  These filters need to be cleaned periodically.  The access to the septic tank is via risers that need to be no deeper than 12″ below the surface of the lawn or yard.  If they are deeper, then new risers should be added at the time of septic tank inspection.

3.  Older systems can have a number of issues that can be expensive to fix.  Cesspools are where the tank and leaching is an all-in-one location and these are now prohibited by the health code and some forms of financing.  Single compartment tanks are also a problem in that they often allow solids to run to the leaching area and that plugs up the soil and leads to premature failure.  Another issue with older systems is the problem of seasonal rising groundwater flooding the leaching area since they were originally installed below high groundwater levels or too close to restrictive layers in the soil.  There’s a lot to know about how septic systems work.

Bottom line on wells and septic systems in older homes, get them tested and confirm that they have the capacity to accommodate the current home use and any expanded use that you might desire.  Here’s a quick video (sorry for wind noise) of a septic tank inspection: